This multi-touch support requires the Linux 2.6.30 kernel. How this works right now is by reading the input events, translating them into multi-touch events using simple gesture recognition, and then sending D-Bus messages over to Compiz to produce multi-touch effects. Right now the code is deemed just a proof of concept, but they are currently working on a better implementation. More information on their current Linux multi-touch work is available through the project web-site. Below is a video they had recorded yesterday showing off some of their multi-touch work on Linux.
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via Twitter or contacted via MichaelLarabel.com.